The coupling between intermediate metabolism and the membrane bound enzyme responsible for cation transport has been studied using 31p nuclear magnetic resonance. Our studies have localized the link to an interaction of membrane Na,K-ATPase with a complex of the three enzymes: glyceraldehyde 3-phosphate dehydrogenase/phosphoglycerate kinase/monophosphoglycerate mutase. We have further shown that all of the intracellular glycolytic enzymes between aldolase and pyruvate kinase are linked in a complex of molecular weight in the range of 10 to the 6th power daltons. We have rebuilt our apparatus to measure reaction kinetics in the microsecond region by the temperature-jump technique and have begun experiments to characterize the reaction of Ca with its ionophore A23187 in solution. We have also begun to look for evidence of the dimerization of amides in the hydrocarbon portion of the lipid bilayer using 13C nuclear magnetic resonance, and have synthesized 13C-valeramide as a probe. BIBLIOGRAPHIC REFERENCES: Solomon, A.K. Thermodynamic aspects of nonelectrolyte permeation of lipid bilayers. Semaine d'etude sur le theme Membranes Biologiques et Artificielles et la desalinisation de l'eau. ed: R. Passino, Pontificiae Academiae Scientarum Scripta Varia 40:193-220, 1977. Fossel, E.T. and A.K. Solomon. Membrane mediated link between ion transport and metabolism in human red cells. Biochim. Biophys. Acta 464:82-92, 1977.